Reversing rolling mills (hereinafter referred to as "Steckel mills") for use in the rolling of steel require peripheral equipment to be located on either side of the Steckel mill. Conventionally included in the peripheral equipment is a pair of pinch rolls to advance the leading edge of the strip of steel being rolled into the bite or kissing point of the reduction rolls, a descaler, and thickness and profile gauges (typically x-ray gauges). Frequently, only a thickness gauge is provided upstream of the Steckel mill, whilst both thickness and profile gauges are provided on the downstream side of the Steckel mill. These gauges measure the thickness or profile of the strip being rolled for the purpose of providing feedback to govern the rolling operation, and to ensure that the strip being rolled will meet customer specifications.
Heretofore, it has been the conventional practice to design and install each of these peripheral devices as an independently designed and installed device.
Partly because of the reversing characteristic of a Steckel mill requiring a strip to be moved alternately in upstream and downstream directions through the Steckel mill, and partly because of the inherent risk of an unruly rogue steel strip, the smaller peripheral equipment is subject to damage. Further, in order to reduce the heat loss of the strip being rolled, the coiler furnace should be located as close as possible to the Steckel mill, yet it is necessary to make room for all of the items of peripheral equipment mentioned and sometimes other items (e.g. an edger) between the coiler furnace and the Steckel mill, so longitudinal space along the length of the rolling line next to the Steckel mill is at a premium.
Consequently, for the foregoing reasons, mill designers prefer to keep to a minimum the number of peripheral devices located between the Steckel mill and the coiler furnace on either side of the Steckel mill, and to attempt to make some of the peripheral units do double duty where possible. Thus, for example, the descaler could be used to provide a cooling water spray of the sort that would normally be applied relatively gently over a relatively large surface area of the steel being rolled for the obtention of preferred metallurgical properties. This is in contrast to the normal operation of a descaler unit, which provides a concentrated high-pressure spray for the purpose of knocking scale off the strip being rolled. Requiring the descaler nozzles to do double duty saves space, but at the expense of quality of product.